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R- V. EQLLQJEQQEMLIQ Q N ROLLER FOR mmmcn GUNS,

APPLICATION FILED SEPT. I3, 1917.

1 ,39 1 1 34;, Patented Sept. 20, 1921.

HIIIIHHHIIIIIHHI III t l-s UNITED STATES PATENT OFFICE.

ROBERT V. MORSE, OF ITHACA, NEW YORK, ASSIGNOR T0 MORSE INSTRUMENT COM- PANY, INC., OF ITHACA, NEW YORK, A CORPORATION OF NEW YORK.

ELECTRIC FUSE-SETTER CONTROLLER FOR ANTI-AIRCRAFT GUNS.

Application filed September 13, 1917.

T 0 all whom it may concern:

flight and location of the burst of the shell are regulated. It consists in general of an apparatus for automatically controlling the setting of the fuse setter mechanism, with the object of increasing the accuracy of fire, particularly when used in conjunction with some form of automatically controlled sight.

In artillery fire against aircraft, the velocity of the target is often so great that the rang and angle of position of the target change too rapidly to permit accurate firing with any fixed setting of the sight and fuse setter. Hence a mechanism is required which will continuously and accurately change the sight and fuse setting to correspond to the actual condition existing when the gun is discharged. Only when this is done can the gunner rely on his gun as an accurate instrument, and make proper allowance for lead to offset the movement of the target during the flight of the projectile. The objects of this invention are therefore to automatically and continuously control the fuse setter; to eliminate errors due to time lag between fuse setting and the discharge of the gun, so that the fuse will be accurately set for the conditions obtaining at the instant the gun is fired; to aid the gunner in estimating the proper lead to offset motion of the target during the flight of the projectile; and various other objects as 'will appear as the description proceeds.

In the drawings forming part of this specification, Figure 1 is a side elevation of an illustrative form of automatic fuse setter controller mechanism; Fig. 2 is a view 'partly in section of the mechanism for eliminating'the time lag error involved in loadingand firing the gun.

Referring to Fig. 1', the control block 51 .is composed of a number of thin copper Specification of Letters Patent.

Patented Sept. 20, 1921.

Serial No. 191,265.

strips 52 insulated from each other and bent in certain curves, as will be explained, and firmly embedded in a mass of hard insulating material, such as bakelite, for example. The edges of the strips 52 are exposed, and each strip terminates in a segment 53, the segments preferably being arranged on the outer edge of the control block 51 somewhat in the manner of commutator segments used in the ordinary D. C. electric motor. For the sake of clearness in the drawing, only a few of the copper strips 52 are shown in Fig. 1, though they may actually number a hundred or more, as will be described. The curvature of the strips 52 is determined as follows: assuming the inner edge of the control block 51 to be graduated as a quadrant from say 0 to 90, representingangle of position of the target or angle of projection of the gun, (whichever is preferred), a curve may be plotted on the control block representing the time of flight for the projectile to reach a certain altitude, for all angles of position or projection between say 90 and 15. The values of time of flight are laid off on radial ordinates measured from the quadrant arc outward, (perpendicular to the quadrant arc),--so that the measure of the time of flight of the projectile is indicated by the radial distance of the plotted curve from the quadrant. For example, take the case of a curve plotted for a target at an altitude of 1000 feet:

for a certain type of gun and projectile the time of flight of the projectile to that altitude for various angles of position of the target might be tabulated as follows Assuming the control block to be graduated as a quadrant from to zero, beginning with 90 at the bottom, or horizontal, (since the line of sight is shown in Fig. 1 at right angles to the bar 57, as described later), we start with a line which at the 90 position on the quadrant is a suflicient distance radially out from the inner edge or radial zero of the quadrant to correspond on some scale to a value of 1.81. That is, at the 90 position, our line has such a location, as would give through the gearing, a setting of 1.81 at the fuse setter. Using that same radial scale, we locate at the 85 position a point corresponding to the value 1.83 at the fuse setter; for the 80 position a point corresponding to 1.87 is located, and so on. We thus obtain a curve which, for a 4000 foot altitude, represents the time of flight or fuse setting. for every angle of position of the target within the limits of the range of the gun. A leparate curve may be plotted for each altitude from say 500 to 5000 yards at intervals of say 25 or 50 yards,and each copper strip 52 is bent so that, after due allowance for the particular form of gearing employed in the mechanism, it will give the desired movement to the shaft controlling the fuse setter,in general conforming to one of the curves described. There are thus provided a number of conductor strips 52 which graphically represent the time of flight to substantially all altitudes for all angles of fire. This control block 51, whatever its form, is then the essential controlling element of the device,- the remainder of the mechanism having the function of causing a contact point 54 to follow any desired strip 52, and transmitting the motion of that contact point 54 to the shaft controlling the operation of the fuse setting mechanism.

By a system of electrical connections to be explained later, it is arranged that all copper strips 52 on one side of a certain desired strip shall have a positive electric potential, and all on the other side of said desired strip shall have a negative electric potential. Thus for example, all strips 52 to the right and below the contact point 54 may be assumed to have a positive potential, and all to the left and above the point 54 a negative potential. From the contact point 54 a conductor 55 runs to the small electric motor 56, which rotates in one direction or the other according as it receives positive or negative potential. Supporting the contact point 54 is the elevating bar 57 which may be provided with rack teeth 58 or other suitable gearing, by means of which the bar 57 may be elevated or lowered by the action of the motor 56 operating through the gearing 59, 60, 61,-the gear 59 being on the shaft of the motor 56 and the gears 60, 61 being keyed to the shaft 7. A switch 63 is provided in the motor circuit.

The apparatus for causing any selected strip 52 to lie between two regions of opposite potential will now be described. In

contact with the segments 53 are two brushes 65 and 66. The brush 65 is connected to a battery B supplying positive potential, and the brush 66 a is connected to a battery B supplying negative potential. The brushes 65 and 66 are separated by a gap slightly larger than one of the segments 53, and are connected to the indicator 67, which, when the brushes 65 and 66 are moved, plays overthe scale 68. The scale 68 is graduated to correspond to the altitude on the basis of which the curvature of the strip 52 was determined, whose segment 53 lies between the brushes 6566. Thus when the indicator 67 is placed at say 3000 yards on the altitude scale 68, the gap between the brushes 65-66 will lie over the segment 53 to which is connected the strip 52 representing the curve calculated for the 3000 yard altitude; and all strips 52 on one side of that particular strip will have a positive potential, and all strips 52 on the other side will have a negative potential.

The operation of the foregoing portion of the apparatus is as follows: The indicator 67 having been set at the proper reading on the altitude scale 68,corresponding to the flying level of the target as telephoned from the observing station,--the switches are closed in the electric circuits. If the contact point 54 is not exactly on the proper strip 52 for the designated altitude, it will receive a positive or a negative potential from the strips 52,depending on which side of the designated strip it lies. The current will flow for example from the battery B through the brush 65 to the segments 53 and strips 52 lying to the right of the designated strip, then to the contact point, thence through the conductor 55 tothe motor 56, which rotates and elevates the bar 57 through the action of the gears 59, 60, 61. As the bar 57 is elevated, the contact point 54 will ultimately reach the particular copper strip 52 corresponding to the designated altitude. This particular strip is not connected with either brush 65 or 66,-since its segment 53 is under the gap between the brushes 65 and 66,and the motor 56 will then stop. If the contact point 54 should go above the designated strip 52 the opposite potential would rotate the motor 56 in the reverse direction and thus bring the contact point 54 down to the proper location. If the gap between the brushes happens to be so located as to electrify adjacent segments 53 oppositely, or if for any other reason there is no dead strip lying between the two regions of opposite polarity, the con-- tact point 54 will follow along the boundary between said regions. The bar 57 is connected ith the sighting mechanism 69 or with some part of the gun which swings with its vertical angular movement, (such as the recoil cylinders, for example),--and as the point 54 isthus swung over the face of the control block 51 the contact point 54 follows the designated strip 52 as described. The shaft 7 rotates proportionately to the elevation of the bar 57, which in Fig. 1, for

example, slides in a guideatta-ched to the so designated. It is obvious that a similar mechanism could give an automatic setting for any designated range, instead of altitude, for all angles of position or projection. But the constant altitude basis is generally preferable to the constant range basis,though either may be used,for the reason that the altitude of the target generally changes less rapidly than the range; also, the altitude setting is the same for all guns, permitting a cotirdinated fire control, whereas the range is different for each gun, making a coordinated fire control impossible with apparatus constructed on a constant range basis.

There has been described above an apparatus which will rotate the gear 61 and shaft 7 in proportion to the proper fuse setting, for a designated altitude,automatically adjusting itself to all angles of fire. However, by the time that the projectile whose fuse was set from such a determination has been loaded into the gun and discharged,

' the angle of fire will usually have changed from that obtaining when the fuse was set. Therefore, what we desire to do is to set the fuse, not for the value which is correct at the time of setting, but for the value which will be correct at the instant the gun is discharged. To accomplish this the following apparatus is provided.

Referring now to Fig. 2,-driven from the shaft 7 is the indicator drum 16 which plays under the fixed pointer 17 and is graduated in units of time, representing the time of flight 0f the projectile. This time of flight is determined by the rotation of the shaft 7 operated by the mechanism above described,as illustrated for example in Fig. 1. This scale 16 and fixed pointer 17 indicate the correct fuse setting at each instant for the angle of fire then existing. The shaft 12 is connected to the shaft 7 by means of a suit-able intermediate gearing 8 arranged to permit the shaft 12 to be given various degrees of lead over the shaft 7. Any mechanical connection which will allow the shaft 12 to be given a lead over the shaft 7 ,-while still being driven from the shaft 7 ,may be used, the connection illustrated by way of example in Fig. 2 being of the planetary gear type, in which the sun gear 9 is attached to the shaft 7. Around the gear 9 are the planetary gears .10 carried in the usual manner on a spider which is keyed to the shaft 12.- The outer casing .13, (which is free to turn on the shaft 7) ,has internal teeth which mesh with those of the planetary gear 10. WVith this outer casing 13 held stationary in the usual man- .ner, the planetary gears 10 will roll around the central gear 9 when it is rotated, giving .a rotation to the spider and shaft 12, which while. slower than that of the shaft 7 bears a fixed relation thereto and hence can be setter 75. If now the casing 13 is rotated on the shaft 7 a certain amount by means of the handle 14, and then held stationary again in its new position, this movement of the casing will cause a proportionate change in the relative angular positions of the shafts 12 and 7, giving a certain definite lead or lag to the shaft 12 as compared to the shaft 7, but without permanently altering the fixed ratio of their rates of rotation. That is, the gearing 8 allows the shafts 7 and 12 to be rotated relative to each other through various angles, while both shafts are being rotated by the motor 56 of Fig. 1. The amount of this lead is controlled through the handle 14, and a movable pointer 15 is connected thereto by suitable gearing so that the distance bet-ween the movable .pointer 15 and the fixed pointer 17 corresponds on the scale 16 to the lead which the shaft 12 has been given over the shaft 7. For example, in Fig. 2, a gear 21 on the hub of the casing 13, drives through a train of fixed gears 23 an internal gear on the inner side of a casing 22, which like the casing 13 is free to turn upon the shaft 7 (in other words, the shaft 7 turns freely within the hearings in the casings 13 and 22). The casing 22 carries a pointer 15, which of course moves in proportion to the amount of rotation given the casing 13 by the operation of the handle 14,the proportionate movement being fixed by the ratio of the intermediate gearing connecting them. As has been described, the movement of the handle 14 determines the lead given the shaft 12 over the shaft 7. Thus the reading under the movable pointer 15 indicates the setting of the shaft 12, while the reading under the fixed pointed 17 indicates the setting of the shaft 7. The shaft 12 is connected through any suitable gearing 73 to a fuse setter 75 of any ordinary type (such as described in the Handbook of the 3-inch Gun Materiel, published by the Government Printing Office, at Washington),-so that the setting of the fuse setter 75 is controlled through the shaft 12.

The operation is as follows :The man operating the handle 14 watches the movement of the numbers on the indicator drum 16,Which move slowly under the pointers 15 and 17 as the gun swings through various angles in following the flying target.

75 utilized to rotate the worm 73 of the fuse Knowing the average rapidity with which the gun crew gets a shell from the fuse setter into the gun and fires,say for example five seconds,he estimates with his eye as the numbers pass slowly under the pointers the number which he thinks will come under the fixed pointer 17 in that length of time. He then sets the movable pointer 15 for that amount of lead. As a shell is taken from the fuse setter he drops his eye and catches the number then passing under the movable pointer 15,and follows that number with his eye until the discharge of the gun. If he has given the correct amount of lead, that number will have arrived at the fixed pointer 17 at the instant of discharge. If it has not yet arrived, he reduces the lead; if it had passed the fixed pointer 17, he increases the lead. As the speed of a well drilled gun crew is a fairly constant quantity, and as the motion of the indicator drum is fairly steady, it is not diflicult to quickly arrive at the proper degree of lead. The result is that the fuse is set at the value which will be correct when the gun is fired.

In connection with the automatic fuse setter there is used an automatic or semiautomatic sight setter which continuously keeps the sight correctly set for the point of aim at the desired altitude regardless of the rapidity of movement of the target. With the sight and fuse thus continuously maintained correct for any movement of the target at the designated altitude, the gun hecomes a continuously accurate instrument which will produce a burst where aimed. It then is possible to estimate the lead, covering the time of flight of the projectile, with a degree of exactness which is impossible when the sight or fuse is given intermittent or approximate settings. The lead which we are here considering-sometimes called the gunners lead, covers the movement of the target during the time of flight of the projectile, and must not be confused with the loading lead, which it is the function of the apparatus shown in Fig. 2, for example, to compensate.

The automatic fuse setter, while not directly concerned with the lead of the point of aim over the actual location of the target, has an important effect in increasing the accuracy with which it is possible to estimate that lead. It will be obvious that that lead must extend over a sufficient time interval after the determination of the original data to allow the fuse and sight to be set, the gun to be loaded and fired, plus the time of flight of the projectile. Where, as in the prior apparatus, the range is determined by a separate mechanism, the fuse setter set by hand, then the fuse on the shell set and loaded into the gun, a loading lead of about ten seconds must be added to the time of flight, (say about five seconds), giving a cover a long period. In the automatic fuse setter, such as has been described, the fusev is set continuously and instantaneously by apparatus which can be made as much a part of the gun as the sight, and the slight loading lead required is introduced simulta neously with the automatic setting of the fuse setter. The loading lead is thus for all practical purposes reduced to zero,--reducing the total interval over which the lead must be predicted from 15 seconds to 5 seconds, in the example given above. In this manner the automatic fuse setter permits a considerable increase in the accuracy With which it is possible to predict the lead and determine the point of aim.

So far we have considered but a single gun, and the apparatus by which it is made a continuously accurate instrument for producing a burst on the point of aim at a designated altitude, together with means for increasing the accuracy with which the point of aim can be determined. As has been stated, designing the apparatus on a constant altitude basis-that is, so that by simply setting the altitude, the apparatus will automatically set itself for any motion of the target at that altitude,the fire of all the guns can be coordinated regardless of their position, simply by telephonic communication with the central fire control ofiicer. Though the range may be different for each gun, the altitude of a given target will be the same for all. Upon sighting a target, the central fire control officer roughly estimates the altitude and immediately orders an altitude setting at all the guns well above the target. The trajectories of the guns focus substantially at the target, but since the fuse setting is for a higher altitude, a broad horizontal barrage breaks out above the target, subjecting it to a rain of fragments. Observing the error in the altitude, (which also can be judged from the breadth of the barrage), the central oflicer orders the altitude settings reduced in rapid steps. As the level of the barrage approaches the focus of the trajectories, (that is, the target), the barrage becomes more concentrated, intense and accurate. The barrage will similarly become a concentrated, accurate fire on the target if the target attempts to escape by rising through it, since in that case the focus of the trajectories approaches the level of the barrage, instead of vice versa. The altitude of this horizontal barrage can be altered as readily as the range of an ordinary barrage, to follow the target if desired. It may be noted that a horizontal barrage cannot be quickly cut through like a vertical or constant range barrage, since an airplane-in normal flight cuts it in its longest instead of its thinnest dimension. The enemy airplane may also be pinched between an upper and lower barrage. The only quick method for an airplane to cut through such a barrage is by a vertical dive; and in my copending application Ser. No. 191,269, filed Sept. 13, 1917, for electric sight controlling mechanism, there is described a simple means by which an automatic mechanism shifts the altitude setting of the brushes to maintain it continuously substantially correct during a vertical dive of the target; that means of course may be used to shift the altitude brushes 65, 66, 67 of Fig. 1, if desired. With the centralized fire control possible with automatic constant altitude apparatus, a prompt and accurate fire control may be maintained.

In the foregoing there has been described a fuse setter controller construction illustrating the general principles of my invention. It will be obvious to those skilled in the art that the apparatus is susceptible to many variations and adaptations in various installations without departing from the scope of the invention as outlined in the fol lowing claims.

1. In an instrument controller for antiaircraft guns, the combination of a control block comprising a large number of conductors each with a segment electrically connected thereto, spaced brushes adjustable relative to said segments, means for supplying positive and negative electricity to the brushes, segments, and conductors, a contact point arranged to play over the conductors, means for swinging the contact point to different positions for various angles of fire, electrically operated means connected with the electric circuit through the contact point for elevating or lowering the contact point whereby it may follow a conductor of the control block, and a shaft through which the motion of the mechanism is transmitted to the instrument to be controlled.

2. In an instrument controller for antiaircraft guns, the combination of a control block comprising a large number of conductors each with a segment electrically connected thereto, spaced brushes adjustable relative to said segments, means for supplying positive and negative electricity to the brushes, segments and conductors, a contact point arranged to play over the conductors, means for swinging the contact point to different positions for various angles of fire, electrically operated means connected with the electric circuit through the contact point for elevating or lowering the contact point whereby it may follow a conductor of the control block, and a shaft Whose motion is determined by the motion of the contact point, a second shaft driven by the first mentioned shaft, and means for varying the angular relation between the first and second shaft.

3. In an instrument controller for antiaircraft guns, the combination of a control 70 block comprising a large number of conductors each with a segment electrically connected thereto, spaced brushes adjustable relative to said segments, an altitude scale and indicator for setting the position of the brushes relative to the segments, means for supplying positive and negative electricity to the brushes, segments, and conductors, a contact point arranged to play over the con ductors, means for swinging the contact point to various positions for various angles of fire, electrically operated means connected with the electric circuit through the contact point for elevating or lowering the contact point whereby it may follow a conductor of the control block, and a shaft through which the motion of the mechanism is transmitted to the instrument to be controlled.

4. In an instrument controller for antiaircraft guns, the combination of a control block comprising a large number of conductors each with a segment electrically connected thereto, spaced brushes adjustable relative to said segments, an altitude scale and indicator for setting the position of the brushes relative to the segments, means for supplying positive and negative electricity to the brushes, segments and conductors, a contact point arranged to play over the conductors means for swinging the contact point to different positions for various angles of fire, electrically operated means connected with the electric circuit through the contact point for elevating or lowering the contact point whereby it may follow a conductor of the control block, a shaft whose motion is determined by the motion of the contact point, a second shaft driven by the first mentioned shaft, and means for varying the angular relation between the first and second shaft.

5. In a controlling mechanism, the combination of a control block comprising a number of insulated conductors curved to correspond to the desired motion of control, means for supplying some of said conductors with a positive electric potential and others of said conductors with a negative electric potential, means for varying the location of the boundary between the positive and negative regons, a contact point arranged to play over the conductors, and an electrically operated mechanism receiving positive or negative current through the conductors and contact point, arranged to move the contact point according to the direction of the current fiow through it, whereby the contact point will seek the boundary between the positive and negative regions.

6. In a fuse setter controller for antiaircraft guns, the combination of a control block comprising a number of insulated conductors curved to correspond to the movement required for the desired fuse setting for all angles of fire at given altitudes of target, means for supplying some of said conductors with a positive electric potential and others of said conductors with a negative electric potential, means for varying the location of the boundary between the positive and negative regions in accord with the designated flying altitude of a target, a contact point arranged to play over the conductors. electrically operated means receiving positive or negative current through the conductors and contact point, arranged to move the contact point according to the direction of the current flow through it, whereby the contact point will seek the boundary between the positive and negative regions, and means for transmitting the motion of the mechanism to a fuse setter.

7. In a fuse setter controller for anti-aircraft guns, the combination of an electrically operated mechanism for causing a movement to correspond to the desired fuse setting for various angles of fire and a constant flying altitude of target, and means for varying the altitude in regard to which the mechanism operates.

8. In a fuse setter controller for anti-aircraft guns, the combination of a mechanism for determining the fuse setting for the existing position of the gun when firing on a moving target, and a second mechanism arranged to give a lead over the first mentioned mechanism to compensate, by continuous anticipation, for the time involved in loading sothat thefuse setting may be correct when the shell is in the gun at a future time when the gun is discharged, where- I by the gun may be maintained with a lead-- corresponding merely to the time involved in the flight of the projectile.

9. In a fuse setter apparatus foranti-aircraft guns, the combination of a fuse setter, automatic means for continuously setting the fuse setter for various angular positions and a constant altitude setting, and means for changing the-altitude setting of the apparatus.

10. In a fuse setter apparatus for antiaircraft guns, the combination ofa fuse setter, and automatic means for continuously setting the fuse setter so that bursts are producedv at a substantially constant altitude above the ground with changing angles of .the fuse setting automatically determined,

to compensate, forthe change in the position of the target during the time of loading.

In witness whereof I; have hereunto set my hand this 7th day of September, 1917.

uROBER-T V. MORSE.

Witnesses:

ELMER H. WANGER. J. S. BARR. 

